Theoretical Study of Temperature dependent Enthalpy of Absorption, Heat Capacity, and Entropy changes for Protonation of Amines and Amino Acid Solvents.

AbstractThe equilibrium constants for protonation of amine and alkanolamine solvents for post combustion CO2 capture are studied in this work using density functional theory coupled with the continuum and explicit solvation shell model introduced by da Silva et al. [da Silva, E. F.; Svendsen, H. F.; Merz, K. M. J. Phys. Chem. A. 2009, 113, 6404]. The temperature dependency of the protonation equilibrium constants is very crucial in understanding the thermodynamics of any solvent for post combustion carbon capture. Theoretically calculated temperature dependent protonation equilibrium constants for CO2 capture solvent are given as input to the Gibbs Helmholtz equations to calculate thermodynamic data of a particular solvent. From the comparison of calculated results from molecular modeling with experimental results, it has been seen that the errors are within experimental error bars